A prior art electric motor for producing mechanical energy from electric energy is illustrated in FIG. 4. The electric motor comprises a rotary axle a, a commutator b and brushes c combined with the commutator b positioned around the rotary axle a, an armature d composed of an iron core and a coil wound around the iron core, and a pair of magnets e positioned outside the armature d whereby the armature d is turned by the attraction between the electromagnets to thereby produce the turning force or the mechanical force. The prior art electric motor has however the problem that, inasmuch as the direction of mutual induction between the armature d and the magnets e fixed outside the armature is circumferential, the inductance distance in the successive attractive and repellent movement effected during the operation of the electric motor, namely, the distance from the start of the mutual attraction between the fixed magnets e and the poles of the armature d to the point at which the attractive force therebetween is directed radially, cannot be smaller than the distance which is defined by dividing the circumferential length of the fixed magnets e by the number of switching poles produced by the armature d when rotated 360.degree., irrespective of whether a brush type or a non-contact type of motor is used.
In an inertia type motor, there is a shortcoming in that the inertia type motor is delayed in actuation thereof and much power is wasted because the inertia type motor cannot operate with its inherent capacity when energized until it arrives at a fixed speed of rotation.